@book{Jarre1990,
  author    = {Jarre, Jan},
  title     = {Die Landwirtschaft und ihre Marktpartner},
  volume    = {1990,5},
  edition   = {1. Aufl.},
  publisher = {Evang. Akad., Protokollstelle},
  address   = {Rehburg-Loccum},
  isbn      = {3-8172-0590-2},
  pages     = {234 S. : graph. Darst.},
  year      = {1990},
  language  = {de}
}
@incollection{Teitscheid1990,
  author    = {Teitscheid, Petra},
  title     = {Kapitel 7.2. {\"O}ffentlichkeitsarbeit},
  series = {BJU Umweltschutzberater},
  booktitle = {BJU Umweltschutzberater},
  year      = {1990},
  language  = {mul}
}